Now cover images use the whole area without any gaps. but image can be cut from some or it's sides depending on browser window size, if you want to show whole image all the time in cover on such pages like groups/spaces/etc, then you can add the following additional style in Studio > Designer > Injections > Head 

<style>
img.bx-base-pofile-cover-image {
    background-size: contain !important;
}
</style>

#tipsandtricks